406
FXUS62 KCHS 081742
AFDCHS

Area Forecast Discussion
National Weather Service Charleston SC
1242 PM EST Mon Dec 8 2025

.SYNOPSIS...
High pressure will extend across the region for much of the
week. A cold front will push offshore Thursday morning with
another cold front possibly moving south through the area over
the weekend.

&&

.NEAR TERM /THROUGH TONIGHT/...
Longwave trough is nicely observed on the mid and upper level GOES
water vapor channels as it moves towards the east coast. With some
weak positive vorticity advection alongside being in the right
entrance region of the upper level jet, scattered light rain is
observed on radar. Not expecting to squeeze out more than a couple
hundredths, with probabilities for a tenth of an inch of QPF at or
below 15% from both the HREF and REFS. Given the continuation
of dreary conditions, expect afternoon highs to struggle to
reach up into the lower 50s across southeast South Carolina,
while those in southeast Georgia will be a touch warmer in the
mid 50s.

For the late afternoon and into the overnight period, a surface low
quickly forms just north of the region under a stronger shortwave,
with a surface high pressure shifting behind it. This will bring an
end to the light scattered rain, with a heightened surface pressure
gradient resulting in slightly breezy conditions, especially along
the coast where gusts into the teens are expected to continue into
the overnight period. Ahead of the surface high pressure, cooler air
is advected down into the region, with overnight lows in the upper
20s to lower 30s for those inland, and lower to mid 30s along the
coast. Combined with the breezier winds, wind chills tonight will
dip into the lower to upper 20s, just high enough to forgo any cold
weather headlines at this time.

&&

.SHORT TERM /TUESDAY THROUGH THURSDAY/...
The Tuesday through Thursday period will offer much improved
conditions compared to the rainy and foggy weather that has been
observed for the past several days. A broad west to northwest flow
will dominate aloft as a large area of high pressure pressure
gradually shifts offshore of the Southeast U.S. coast. A broad
trough is forecast to dig across the eastern CONUS Wednesday into
Thursday which will help drive a weak cold front offshore Thursday
night. Moisture return ahead of the front looks meager at best with
a dir airmass progged to hold over much of the Gulf. PWATs are
forecast to surge somewhat right ahead of the front itself, but will
remain well below the 1" mark. This lack of moisture coupled with
the corridor of great quasi-geostrophic forcing progged to remain
displaced well to the north, suggests the front will pass through
dry with little prospects for measurable rainfall. Temperatures will
moderate ahead of the front with highs reaching the upper 40s/lower
50s Tuesday and lower-mid 60s Wednesday into Thursday. Lows
Wednesday morning will drop into the upper 20s well inland to the
lower 40s at the beaches with upper 30s/lower 40s inland with upper
40s/near 50 at the beaches Thursday morning.

&&

.LONG TERM /THURSDAY NIGHT THROUGH SUNDAY/...
Quiet weather will generally prevail into the weekend as high
pressure slides east across the Southeast U.S. and eventually
offshore. A cold front is forecast to backdoor in from the north on
Sunday as as the beginnings of a cold air damming/wedge take shape.
There are considerable timing differences noted with the southward
moving wedge front Sunday. The timing of the front will closely tied
to any possible surface cyclone that develops along the front. For
now, both the GFS and ECMWF ensembles, including any AI
counterparts, keep any surface low weak and tracking well to the
north. The area may be fully wedged in on Monday with cloudy and
cool conditions prevailing. There was no reason to deviate from the
08/13z NBM at this time given the uncertainty, although NBM-based
temperatures Sunday and Monday may end up being too warm depending
on how the wedge evolves.

&&

.AVIATION /18Z MONDAY THROUGH SATURDAY/...
18Z TAF - While there has been some temporary improvements to the
flight categories across the tri-county region, MVFR to LIFR cigs
will be continuing/building into the region for the remainder of the
afternoon hours. As surface high pressure builds into the region
this evening and overnight, the LIFR-MVFR cigs continue, though
drier air mixes in and scours out the cloud coverage Tuesday
morning. Winds will remain on the gusty side this later this
afternoon and evening, decreasing into the morning hours on
Tuesday.

Extended Aviation Outlook: There are no high confidence
concerns.

&&

.MARINE...
Through tonight: Northerly flow across the local waters will
strengthen through the late afternoon becoming a solid 15-20 knots
by sunset. Winds will strengthen further overnight through the early
morning hours with increasing potential for 25 knot gusts,
especially in the nearshore waters from South Santee down to Edisto
Beach, SC, and the outer waters from Savannah to Altamaha Sound GA.
Seas will be increasing up to 5 feet in the outer reaches of the
nearshore waters from South Santee down to Edisto Beach and the
outer waters from Savannah to Altamaha Sound GA late in the day.
Then overnight seas will tick upward about another foot, bringing a
period of 6 ft seas into the aforementioned waters. The previously
issued Small Craft Advisory looks to be in good shape, so no changes
were made.

Tuesday through Saturday: Winds and seas will diminish below
advisory levels across the South Santee-Edisto Beach nearshore and
Georgia offshore waters by mid-morning Tuesday. Otherwise, winds
will turn more southerly for Wednesday and more westerly Thursday
into Saturday as high pressure slides offshore and a cold front
pushes offshore. Winds and seas could surge to Small Craft Advisory
levels Wednesday night/Thursday morning immediately ahead and just
behind the cold front. Advisories at the most likely over the South
Santee-Edisto Beach and the Georgia offshore legs where the latest
LREF probs for gusts >25 kt is running 50-80%. Otherwise, winds and
seas will remain below Small Craft Advisory thresholds.

&&

.CHS WATCHES/WARNINGS/ADVISORIES...
GA...None.
SC...None.
MARINE...Small Craft Advisory from 4 PM this afternoon to 10 AM EST
     Tuesday for AMZ350-374.

&&

$$

NEAR TERM...
SHORT TERM...
LONG TERM...
AVIATION...
MARINE...